Drilling apparatus



Jan; 21, 1958 Filed March so', 1953 G. H. FUEHRER DRILLING APPARATUS Y 5 Sheets-Sheet l 1N 650265 ff. FUE/fee@ Jan. 21, 1958 G. H. FUEHRER DRILLING APPARATUS 5 Sheets-Sheet 2 Filed March 50, 1953 7 9 d, G o e J E 7 4 e R6 a E G GM ww 7 A 9 E Y 7 v Ww m mmm m a W A m s /M/ 1% W. y. m I. 1| l] I I. G5. 5 9H Il... M Il 7 m 9 mm 8 m 2 L IMJ xwv A ls, /T\\\\\\\\\\\"VWC%/W Jan. 21, 1958 G. H. FUEHRER 2,820,511

j DRILLING APPARATUS Fileduarcn so. 195s 5 sheets-sheet 3 I@ 50 wI ,47 @Q4/Eff Jan. 21, 1958 G. H'. FUEHRER' 2,820,611

DRILLING APPARATUS Filed March 30, 1953 y 5 Sheets-Sheet 4 v v |9172 v |5517@ f |55 52 www Jan. 2l, 1958 G. H. FUEHRER 2,820,511

DRILLING APPARATUS Filed March 30. 1953 5 Sheets-Sheet 5 PFG-.19.

United States Patent O DRILLING APPARATUS George H. Fuehrer, Downey, Calif., assignor to Thor Power Tool Company, a corporation of Delaware Application March 30, 1953, Serial No. 345,340

16 Claims. (Cl. Z55-51) The present invention relates to portable drilling apparatus, and particularly to a boom-type drill support the boom of which is capable of being vertically and horizontally pivoted to a variety of drill-locating positions and locked in such positions by a control located adjacent the drill itself.

In mining and tunneling operations it is necessary to provide means for maintaining the heavy drill mechanism in adjusted positions adjacent the tunnel face being operated upon. This may be accomplished by providing a manually movable frame structure, but the great amount of time lost in ysetting up and moving such a structure has resulted in recent years in the use of an easily ymovable apparatus known as a boom jumbo or a drill jumbo. Such an apparatus usually comprises a truck movable on `a trackway and incorporating a forwardly extending arm or boom adapted at its forward end to support the drilling mechanism, which is conventionally of the drifter type incorporating means to feed a drill bit into the rock. In Iorder to provide for the ready positioning of the drill at any part of the surface to be drilled, the boom is normally pivotable about both a horizontal axis and a vertical axis, and the drill mounted at the boom end is likewise pivotable about both horizontal and vertical axes. Since it is necessary for eiciency that the operator of the apparatus stand in a position closely adjacent the drill itself, instead of adjacent the truck upon which the boom is mounted, it is highly desirable that all control devices be located at the drill instead of on the truck. It is also important to the proper operation of the apparatus that the boom be rigidly locked or braked in each desired position, but that upon releasing of the brakes the pivoting of the boom about its vertical axis be substantially frictionless since this pivotal movement is performed manually.

With an appreciation of the above problems characterizing the iield of boom jumbos, it is an object of the ,present invention to provide a new and improved means for effecting locking of the boom about both its horizontal and vertical axes by improved control means located at the drill itself to render unnecessary any movement by the operator back to the truck on which the boom iS mounted.

land constructed to effect raising or lowering of the boom,

,as well as locking or unlocking of the boom about both of its axes.

These and other more specific objects and advantages vof the invention will appear upon a reading of the following specification and claims and upon considering in con- 2,820,61 l Patented Jan. 21, 1958 ice 2 nection therewith the attached drawings to which they relate.

1n the drawings:

Figure l is a side elevational vview showing the boom jumbo of the invention in both depressed and elevated conditions;

Figure 2 is a top plan view of the boom jumbo illustrated in Figure l;

Figure 3 is a vertical sectional view taken at line 3--3 'of Figure 2 and showing the means for locking the boom against pivoting about its vertical and horizontal axes;

Figure 4 is a transverse sectional view of the upper end of the boom, taken along line 4 4 of Figure 3;

Figure 5 is a longitudinal central section of the forward boom end, taken along line 5--5 of Figure 2;

Figure 6 is a transverse section of the forward end of the boom and showing the improved control valve of the invention, taken at line 6 6 of Figure 5 and is viewed in the direction of the arrows;

Figure 7 is a sectional view along line 7-7 of Figure 6 and illustrating the detent means for locking the boom control valve in its various positions;

Figures 8, 9 and 10 are sectionalviews taken along line 8-8 of Figure 6 and respectively showing the control valve in its locking, exhausting and boom-raising positions; A l

Figures 11, 12 and 13 are sectional views taken along line 11-11 of Figure 6 and again illustrating the control valve in its locking, exhausting and boom-raising positions;

Figures 14, l5 and 16 are sectional views along line 14-14 of Figure 6 and correspondingto Figures 8-13 to respectively illustrate the boom control valve in the Asame three positions;

Figure 17 is a transverse section of the boom end, taken at line 17-17 of Figure 5;

Figure 18 is a transverse boom section along line 18--18 of Figure 5 and illustrating the locations of ,the various air and water conduits; and

Figure 19 is a schematic diagram of the air system of the invention.

Referring to the drawings, the boom jumbo may be seen to comprise generally a truck 20, an upright boomsupportiug and pivoting structure 21 rigidly mounted at the forward portion of truck 20, a forwardly extending boom 22 pivotally mounted on boom support 21, and a drill mechanism 23 mounted at the forward end of boom 22 for operation on the tunnel face to be drilled. According to the present invention a raising and lowering mechanism 24 is provided to vertically adjust boom 22 and drill mechanism 23; locking means 26 are incorporated in boom support 21 to prevent pivoting of boom 22 about both horizontal and vertical axes, and a master control valve 27 is mounted at the forward boom end to operate both the raising and lowering mechanism 24 and locking means 26.

The truck 20 may be any suitable type, here illustrated as mounted on Wheels 28 which ride along a trackway 29 in the floor of the tunnel being constructed. At its rear end the truck 20 usually carries a vertically extending jack mechanism, not shown, adapted to engage the tunnel roof and lock the truck against forward or backward movement during the drilling operation. In addition, the truck is usually provided with suitable track clamps 31 and with brake shoes, not shown, to further insure that the truck will be rigidly maintained in each operating position.

Referring to Figures 1-3, inclusive, the `boom-supporting and pivoting structure 21 comprises a `tubular pedestal 32 which serves as a bearing for a cooperating column 33, the column being mounted concentrically over the Apedestal 32 for adjustable support of boom 22. In addition to the seat the apertured center portions of piston discs 72 and 73. Cylinder 83 is threaded over the lower end of connecting rod 71, there being a cotter pin 87 to insure that the connection is properly maintained. Downward shifting of disc 73 to depress connecting rod 71, through operation on shoulder 85, is eected by admitting air into a lock pressure chamber 8S. The upper wall of this chamber is formed by a disc 89 corresponding to disc 73 and seated at its upper peripheral surface on a shoulder portion 91 of pedestal base 34. The chamber 88 is sealed against leakage by a plurality of O-rings 92 seated in suitable grooves in discs 73 and 89 and in plug cylinder 83. Downward shifting of piston disc 72, which operates on shoulder 84 to lower connecting rod 71, is effected by admitting air into a lock pressure chamber 93 defined by the upper surface of disc 72, the horizontal interior wall of pedestal base 34, and by O-rings 94 at the outer and inner edges of disc 72. In addition to O-rings 94 an O-ring 96 s provided between the upper lportion of plug cylinder 83 and the cooperating cylindrical surface of pedestal base 34 to aid in prevention of leakage from chamber 93.

The admission of air into the hollow pedestal base 34 is effected from an air fitting 97 and through a passage y98 in base 34 in the case of chamber 88, and passages 99 and 100 in the pedestal base in the case of chamber 93. The passage 99 communicates through a horizontal passage 101 and vertical passage 102 in the pedestal base with a chamber 104 formed between a shoulder portion 106 of column 33 and a cooperating grooved shoulder 107 formed in the pedestal base. Chamber 104 is sealed Iby suitable O-rings 108 and communicates through a passage 109 with a large central chamber 111 in pedestal 32. The lchamber 111, which may be termed the air reservoir, is sealed against leakage by an internal ange or neck portion 112 at the upper end of pedestal 32, and by O-rings 113 at the upper and lower ends of connect- -ing rod 71. To complete the air conduit and reservoir system in the boom support and pivoting structure 21, a suitable check valve 114 is provided in passage 101 and adapted to prevent air from returning from chamber 104 to air tting 97.

In the operation of the above-described, air conduits, chambers and related elements, the applying of air pressure to fitting 97 causes this pressure to be transmitted to chambers 93, 88, and through check valve 114 to chatnber 104. The pressure in chamber 104 will, acting upon the shoulder 106 of column 33, tend to maintain the column and related elements in an upper position. However,- rthis upward force is greatly overbalanced by the force exerted on pistons 72 and 73 in a downward direction, since the combined piston area is much greater than that of the horizontal walls of chamber 104. It follows that the pistons 72 and 73 will pull connecting rod 71, and thus column 33, downwardly until the lower horizontal wall 116 of column base 37 engages a brake facing 117 on the upper horizontal surface 118 of pedestal base 34. The surfaces 117 and 118 are thus locked, and rotation of the column 33 about pedestal 32 is effectively prevented as is lateral shifting or swinging of the drill mechanism 23 and boom 22. In addition, the boom 22 is locked against rotation about the horizontal axis through tightening of hinged cap 70 on trunnion 41.

Upon release of the air pressure applied to tting 97, and consequent Venting of the air in chambers 88 and 93, the downward force of tandem pistons 72 and 73 will no longer be present. The air pressure will remain, however, in chamber 104, since check valve 114 prevents any venting. The upward force on shoulder 106 of column 33, exerted by the remaining air pressure in chamber 104, will then be operative to lift the column 33, connecting rod 71, and piston discs 72 and 73 to their upper positions. In addition, the hinged cap 70 is released to permit free movement of trunnion 41 for pivoting of the boom about a horizontal axis, and column surface 1,16 is disengaged from brake facing 117 to permit free pivoting of the boom about the vertical axis. The pivoting of the boom about its vertical axis is relatively frictionless since the air pressure in chamber 104 provides an air bearing or cushion which supports the weight of the column and boom without in any way increasing the frictional resistance acting to prevent horizontal boom swinglng.

The air-bearing support of column 33 is maintained regardless of slight leakage of air from chamber 104 and even during complete disconnection of an air pressure source from fitting 97, as during transporting of truck 20, by the feeding of air from reservoir 111 through passage 109`into chamber 104. Stated otherwise, the air under pressure which was initially passed through passage 109 into reservoir 111 during application of air pressure to fitting 97 serves as a cushion or balance to maintin the air pressure in chamber 104 regardless of slight' leakages around the various O-ring seals of the apparatus. Furthermore, the air reservoir 111 operates to prevent compression of the air in chamber 104, so that the upward force on shoulder 106 is constant regardless of the upper or lower positioning of column 33.

The air supply system to -ltting 97 for operation of the locking and air bearing 'means as above described comprises a rubber hose 120 (Figures l and 4) leading to a fitting 121 at the inner end of the boom. Referring `to Figures 3 and 4, fitting 121 extends through sleeve 44 into a suitably shaped end plug 122 which is Welded in sleeve 44 adjacent the upper end of boom portion 46. Fitting 121 communicates through a longitudinal passage 123 in the end plug with a pipe 124, the latter extending for the entire length of boom22 and to the main control valve 27, as will be described in detail subsequently. Referring particularly to Figures 3 and 18, a relatively large air supply pipe 126, which communicates through control valve 27 with the pipe 124, also extends for the full length of boom 22 and is threaded into plug 122 as in the case of pipe 124. The air supply pipe 126 communicates through longitudinal tnd transverse passages 127 and 128 in end plug 122 with a fitting 129 (Figures 1 and 2) and an air hose 131 leading to a suitable air pressure source, indicated generally at 132 in Figure 19. The admission and venting of air through Iitting97'at the base of pedestal 32 is thusk controlled by valve 27, the latter being shifted by an operator disposed at the forward end of boom 22 as is desired.

The piping system in boom 22 further comprises a water pipe 133 (Figure 18) which extends for the full length of the boom and communicates through a passage 134 in end plug 122, and a fitting 136 with a hose 137 connected to a suitable water source. The various pipes 67, 68, 124, 126 and 133 may be rigidly mounted within boom 22 in any suitable manner, as by spiders such as indicated at 138 in Figure 5, and may extend through the boom knee member 48 by means of any suitable'coupling elements, not shown.

Referring particularly to Figures 5, 17 and 18, thefive pipes or conduits extending through the tubular horizontal boom portion 47 are circumferentially spaced, as indicated, with the relatively large air supply pipe 126 disposed above raise and lower pipes 67 and 68, and the lock pressure and water pipes 124 and 133, disposed, respectively, 'below pipes 67 and 68. yAll of these pipes are provided with sliding seals, such as the sealing arrangement 139 at the end of air supply pipe 126, which connect the respective pipes with corresponding passages in the solid end portion 52 of the valve housing and drill support element 50.

Referring rst to the water supply pipe 133 (Figure 18), it communicates through axial and transverse passages 141 and 142 (Figure 17) with a hose 143 leading to drill motor 58 for supply of water to the drill bit 60.

` WaterV may thus be Supplied to the .drill mechanism. .2.3,

-Valys 1.5.32 .-(Ff'igure llis agqvided 'i1-.series with vthe Qontrol Yvalve- ;ISS-:agcl shutoff Yvalve .-llnwhile :th

. muliigates. f thraugh. relativelyfsmall ,passage l 214% with a secegdanfl smaller-hose-.llltliigure-a) leadingiztatlae fltitepaietor S7- Asuitahle shntet valve `i511hav-iin; a `.ll-Slianetlpartiva.15.2. mounted.' tvalve chamber .145 @Parable te 'seleetiyelyV @een and. bloc the: @cassation between. the. air inlet.. passage :14a/.and passage .1146-, :leading. tQithe drill and dtitternioter .-Inadditiena-eontrol taff valver t1.5.1.1@salarial -admsianzef ir te 'the drilliniotnr Stir The. drill mater. 458 .is thus under cent-rol Qfshoth e drifter motor 57 is:rzontfelletbyv ,shntetfayalvetl-lsand by other suitable valves, s. notflshewn.

The master control yvalve-2,7 will next be :described together with its operation in controlling-f the owxolf @Air between air Supply 'pineiizand lock,.pressure-l ipe 12,4,.and :between raise` and :1ower."pipes 167. an 168, The Valve 27 comprises @elongated-valve cylinderfflSS. monntedin a corresponding.transverse bore Wln'ch lex:- tendsthrough. .theisolid .end prtion52 of the I'yalveyhcnls.- ingand .drill snpport.member;,5,0. The horeifonwalve cylinder 15,5 also extends throughga laterally extending boss portieri Y156 of.tlztezmemben5.0"as` :best Lsilent/.nain 1igurel 6,. .At opposite. endsof valve .ylinderltl :are provided :a pairof handles.- 158 and .159;the former tof which rismonntedy adjacent the boss. portion 1561by1means of a, screwll and key pin y162, andrthe latterrofifwhich is integral withthe valve cylinder.V Referring to Figunel; apsemi-circnlar groove 163. in; valve..cylinder155 .istpros vided with: notches- 16410 16.8, f. inclusive, adapted :to i se-` lectively receive a vspring-.pressed .detent 169.. In'ithiS manner, the'valve 27 is .maintained LinuanyS one of .its five. operating positions'at all tignes except dnringnmanual turning of a handle S or.15Qlbytanioperatori:disposed.qn..either side oftheboom. 1

The position of control:va lve f27 to. eiectfadnn'ssinn f' from. supply'pipe 126 to :lock pressure pipel 124 for locking: QfthebooIn-.abnutj'bcith'vertiqalafanthherizontal axes as discussed i11= connectionwitll lockingfmeans'fz in Figure f3, is. thatfin which.- they .valves handles; 1581and 159Qare pnintngtidownwardly and detent .169tzis registeredin noten-166 as-illustrated inzFigure I7.; whenfthe valye;.is;in this'spositiqulallock :pressure ciraittmaybe ttaedrxfrom ,supply -pipeeflz' :and passage htdto Ya communcatinggannular grogne. 171 inzvalve. cylinder:r 155 (Figures-.51am 61), .zthenzthnoughrna longitudinal .valve passage 17.2 (Figures .Szxand rigtlhrough `13) .tolatcoms municatinggradial valne:passage 1753 (Figures '.8' through 10). The radial Valve passage176;.issatithisntimerregisf s tered,:as"sho.wm inlF-i'gurei, 'Wit-h a generally longitudinal passage :17.4. in. end' .pontion :52. Y .From passage `174111:: air .ow i is (throughv :communicating ltransverse passage 176 (liigurhesg, '10;1and f7/)emga secondY longitudinal passage 177 in .endgportioni'-Z'. Passage177iconnects tollols. pressure. pipe 12.4,Y these.y .elements Vbeing aligned as shownin Eigunes 1.7. a 1:8, v. Whenthesconttolvalve .i all Qfzthe Otherpassagsin valve/cylinder 1 55 are blacked, as VWill-,be subsequently descr.ihed,4 sa. lhattheairmotor; 66 islnot vOperating .and an venting staking place.

"To cut off 'thesupply of air from pipe 126 tov loclggpresf A.nine l12.4,. .and additiqnally t9 vent the air. fnom ghamlieis' ande93..(Figure)A fior release ofthe'locking faction, control valvev 27T-is rotated in veither'direction fsjfon position. Thus-When either of notches-165 erf-167 isi'regisltered WithdetentflQ theiga-ir'fin the lockpressure chambers isa-vented -a'n'clf the brakingv action lr"e1ease`d-=prior assale-ii te generaties ai eboom-naising motor 166;, f-which'isteented tht.. u l1situationof. yalve27f-unt`l ither -,of..r,1.atcl1.es el." 63 @sisters withdatent.1169.Y B terrine ,particularly uresf, A6. .and ..9,; :the .situation .is :illustrated where .the :valve gylindertis vrotated une` .step GIOCKWSQ, thati's .te Tsay, until notch .465 .registers with detent 2169;. .lt-will khe. n; .t.edtf.r..f m Figure i9 that'the radialvalvepassageil'l rleaning .to air supply pipe 111.26 is. novi/blocked andtthat llgitudinal Vpassage 117:4:newregisters with .aehamher l inwalve :cylinderA 155- "fhe Vhainher .17:19 .commuilir whether-the'valve is; rotated .onezstep .:elockwise-ortconnf telielqekwise. for selective-utilization of ehambersd'zs or 183, the various ports leading:ltoaboommaisingnd laweringfmotar. 66am .blocked iand ztbisq=-motor :islnot @pegatina t iReferzingtnextto Figures 5.', 6,117. andnl, the "rais' pipe, `67.1.=f mmkm.ates. with1a .passage a185-.-extending lhltoughzendportien 52'for-1tem1ination at the. -bore v:for :valve c -ylinden.155.` iCorferspnndingly, Alo.we1". :pipe .1,68 communicates .through a passage l186 with'thewvalve'chamhergsbothofthe@ passages 1185 .and .1-86 :being Aaxial tex.- tensions. of'v .the .pipesto .which stheycrespectively aconnect. -W'hen the/:controlgvalve isinthe clockwiserrotatedposii tion shown iin'Y Figures .13A and. 1:6, .with Vnotch '164; :in registry vwith .detent y169, aboom-raisi-ng circuit may be traced fromfairisupplyzpipe 126, and :passagev 144, through annular groeve. 171 V(Figuresf 51 andv 6)., tov a: longitudinal groom-M188 `i'nzthe surface.. of valvecylinder 11,515. '-The ,groeve :1881 extends into. registry with .passage `f""leacl ing to".raise pipe 675. The resulting transmission-etait' through pipe 67 .to=airlrnotor 66 operates, asfpreviou'sly indicated, :to elevate boom 22. lAt the `same:tirne;th\' rt air is admitted to pipe 67 to elect boom `elevation,:esihaust :air is `vented Strom moton`66-th1=oughlower fpipe 68. `Thiszventing circuit may be rtracedf from `pipef through: passage 21862 and' `a radial-valve passa-ge l1&9 le'adingsto -anextension off-axial valve passage 182 -andfthus tofthegatmosphere. i Duri'ng thef dese'ibedoperatjenV 'ofi air motorL 6611 te eleyate booin 22,'- theA ventingeireuit froml Vthe Vrlock grpressure Chambers ismaintained due ytofeontinued registry of passage174-withivalve-chamber 179J as illustrated inFigure i110. I-'tffolllawsthaty Yventing off the -air inthe lock pres# sure eham'bers- Willlresultieven thonghtthecontrolf-valveis rapidlyshiftedfirom its; loel'tingto4 boom elevating-*posit-ion,--andlfthat" the? livecam`V raising; moton 66L neven faet against the` `'-locllsing saetli'on `fen an appreciablef l'engthof time. 4

Y Ifn'- order t@ opera-tethe rnotoffin the reverse-4 dii-eetion andtithns `lower-'the boom, 'contrl'yal-vei's rotated VI-SGYdegrees 'from thea'positionsshown in'Fzigures 10,?13 andiA 16. Aire then 'f'ovvs motor 66 from air" supply pipev yltheuglzr a circuit; ineludingpassage f 144, annular groovew 171, a `longitudinal*valve-groove 1-9r1rdiametri`ally opposite groove"lbut'axiallyfdisplaced therefrom; passage '1-1`-86,-an`d "flowerit-pipe 68.'l Similarly, vrarr-exhaust path; is ornpl'etedifrom `-^rai se' pipe [67 and passage' J185, through a radial4 passage `$11972, 'ventingpassagef-SZ, and totheatmqsphee. *It Will-benQted that- Whenthefontrolvalvef2-7`-1is in^this-position eiectingloweringoff'the hoorn/notch liisnegisteredi-vith detent 169, andm val-ve chamber 13831: ('F-iglnre l0) "is registered with passage 1741-, 'sothath-afventing path is completedlfrom ythe lockll'pressureehanabers as i-ntheboomfraising situation;Y

Y lathe/operation of theaboomjumbo,assume-sthatthe boem is--inthe=depressed= positionshownin -solidilines safes through. afdiametrie yalve passage :18.1. with-.an

-68 and out axial passage 182 in the control Valve.

in Figure 1, and that the boom has been swung about its vertical axis until drill bit 60 is at the desired lateral position adjacent a portion of the tunnel face being operated on. Control valve 27 is then shifted to its boom locking position, with the handles 159 and 158 pointed downwardly as shown in Figures 6, 7, 8, 1l and 14. A locking circuit is then completed from air pressure source 132 through hose 131, pipe 126 within boom 22, the previously described passages in control valve 27, lock pressure pipe 124, tting 121, air hose 120, fitting 97 in pedestal base 34,-and through passages 98, 99 and 100 to lock pressure chambers 88 and 93. The piston discs 72 and 73 are thus shifted downwardly to lower connecting rod 71 and tighten the hinged cap 70 against the upper surface of boom trunnion 41 so that the boom is locked about its horizontal axis. The lowering of the piston discs 72 and 73, and connecting rod 71, further operates to lower the entire column 33 until wall 116 of column base 37 locks against brake facing 117 to prevent rotation of the boom about its vertical axis. As the air pressure is thus supplied to effect locking of the boom, the air reservoir 111 within pedestal 32 is filled through a path including check valve 114, passages 161 and 102, chamber 104 and passage 109.

Upon completion of the drilling operation at a particular portion of the tunnel face control valve 27 is rotated one step in either direction, for example to the position shown in Figures 9, l2 and l5, to block the supply of air from the pipe 126 to lock pressure pipe 124. Pipe 124 then becomes a venting conduit to vent the air from lock pressure chambers 38 and 93 through a circuit the reverse of that above described, and out axial passage 182 in valve 27 to the atmosphere. Although the air is thus vented from lock pressure chambers 88 and 93, check valve 114 (Figure 3) prevents venting of air from chamber 104 and reservoir 111. The air pressure in chamber 104 is then operative to elevate the entire column 33 and boom 22 to provide an air cushion or bearing. The braking action being released, the drill may be laterally shifted, in a substantially frictionless movement, to any desired position by the operator located at its forward end.

To raise or lower the boom the operator shifts control valve 27 to one of its extreme positions, for example the oneV shown in Figures 10, 13 and 16. A circuit is then completed through the previously described valve passages from air supply pipe 126 to raise pipe 67. This operates motor 66 in a forward direction, for example until the actuating arm 62 is extended to pivot boom 22 upwardly to the extreme position shown in dashed lines in Figure ll. During the boom raising operation the exhaust air from motor 66 is vented through lower pipe Furthermore, the venting of the air from lock pressure chambers 88 and 93 is continued as previously described. To lower the boom 22, for example after appropriate boom locking and drilling operations, the control valve 27 is rotated to the position of 180 degrees removed from that shown in Figures l0, 13 and 16. The direction of air ow in pipes 67 and 68, and thus the direction of rotation of`motor 66, is then reversed, with the pipe 68 conscribed in detail is fully capable of attaining the objects and providing the advantages hereinbefore stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction y"or design herein shown other than as defined in the *appended claims.

10 I claim:

1. In a rock driiling apparatus for use in mining and tunneling operations, a movable support, a pedestal having a hollow base immovably anchored on said support, said pedestal base having a relativeiy largeA upper surface, a column mounted on said pedestal for iongitudinal and rotational movement relative thereto, said column having a base flange the lower surface of which is adapted to lock with said upper pedestal base surface, a drill supporting boom mounted at the upper end 'of said column and rotatable therewith to position laterally a rock drill relative to the tunnel face to be drilled, uid operated means disposed in said pedestal base and operably connected to said column to effect downward movement thereof, and means to admit fluid pressure into said pedestal base to shift said fluid operated means, column and boom downwardly until said pedestal base surface and said lower surface of the base ange of the column are in locking engagement preventing rotation of said column and boom.

2. The rock drilling apparatus as claimed in claim l, wherein air bearing means are provided to normally maintain said column and boom in an elevated freely rotatable condition, said air bearing means including a chamber defined in part by said pedestal and in part by said column, and wherein means are providedto introduce into and maintain in said chamber air under suiicient pressure to maintain said column and boom in said elevated rotatable condition except during said uid pressure shifting of said fluid operated means.

3. In a rock drilling apparatus for use in mining and tunneling operations, a truck, an upwardly extending pedestal anchored on said truck, a column mounted on said pedestal for rotation about a Vertical axis and for longitudinal shifting on said pedestal, lock surface means associating said column and pedestal 'to effect locking of said column against rotation about said'vertical axis upon longitudinal shifting of said column to a predetermined position, a boom, a pivot member rigidly associated with said boom and journalled in the upper portion of said vcolumn for rotation about ahorizontal axis, means to rotate said boom and pivot member about said horizontal axis, a drill mounted at the outer end of said boom for lateral adjustment through rotation of said boom, pivot member and column about said vertical axis and for vertical adjustment through said rotationV of said boom and pivot member about said horizontal axis, a piston mounted in said pedestal, and means operably connecting said piston with said column and pivot member to shift said column to said predetermined position and to effect simultaneous locking of said boom against rotation about said horizontal and vertical axes upon fluid shifting of said piston to a locking position.

4. ln a rock drilling apparatus for use in mining and tunneling operations, av truck, an upwardly extending pedestal anchored on said truck, a column'mounted `on said pedestal for rotation about a vertical axis and for longitudinal shifting on said pedestal, lock surface means associating said cblumn and pedestal to effect locking of said column against rotation about said Vertical axis upon longitudinal shifting of said column to a predetermined position, a boom, a pivot member rigidly associated with said boom and seated on the upper portion of said column for rotation about a horizontal axis, a cap member seated over said pivot member, a drill mounted at the outer end of said boom for lateral adjustment through `said piston and cap for tightening of said cap into locking engagement with said pivot member upon shifting of said piston to a locking position, said piston also serving when in said locking position to hold said column in Said .pre-g Vendof "said .column forzrotation offsaid vboom aboutfa v horizontal .axis,a cap member pivotally connected tothe upper-'tend osaid column and seated over said boom pivot portion, xapiston mounted interiorly of said :pedestal, '.aconnecting -rod extending from said piston for .connection vto said cap member. at the opposite sideof said boom pivot portion from kthe pivotal connection `betweensaid cap member and column, and` uid pressure .means to shift said piston downwardly to a locking lposition; said .piston and .connecting rod Athen -serving to tighten said. cap .member into locking contact withfsaid yhoorn-pivot portion ande preventrotation of ysaid'boom about said horizontal axis, and .to shiftsaid column :and -boomdownwardly until'. said :pedestalfand .column lflanges are.in;locking engagement and lhoorn rotation aboutsaid vertical. axis prevented.

. 6. .The :invention as claimed in bearing .means are provided to vvnormally :support vsaid column and boom in a freely rotatable elevatedcondition, said :air bearing means including :means to .define acol- -lapsible chamber. the opposed'swalls of which arelformed byifsurfaces of said pedestalgandxcolumn, .and3wherein means .areiprovidedto introduceinto and 'maintain .in said` chamber .air under pressure; suihcient'to .supportsaid column :and boom .1in elevated. freely 'rotatable condition .'exceptzduring.- maintenance ofrsaidpiston ;in said locking position.. byesaidl fluid pressuremeans.

7. lu :a-drilling.:apparatus.:forzuse inzmining and-tun- .neling-operations, 1 a movable .support, a .pedestal :..an-

K -chored on asaid lsupport,I 1.aA column .f rotatably supported .byzsaidpedestal'for rotation .abouti `a @vertical axiscpassing therethrough,'i alboom` pivotally:` connected tozthefupper .portionuof 1saidzcc'Jlurnn'1ifor.iv rotation. about. la horizontal 'axis,=;aidrill' mounted-.'attthe outer: end"of.said.boom,1said .drillzbeing 'ilaterally :movable '.L through .pivoting of .said :boom about:v said -vertical. :axis .f and vertically. frmovable throughpivotiugsof saichhoomaaboutzsaid. .horizontal faxis, .a rchamber` '.formed; between. :cooperating rgenerally; horizontalsportionsaof.. saidapedestal .and column,; and -rneans .c'lairn5, wherein air i .tomaintainfsucient fluidipressurergtins'said.:chamber to 1 provide rfluid fssupport forifsa'id :.column andxhoom, ssaid fluid support arrangement):permittingsubstantially 'fricltionless'ipivotinggoffzsaid yboom :about :said vertical axis toriaeilitatelateralf'adjustment ofzzsaid drill.

. 28. @In .fafrocktdrillingapparatus for use .in imim'ngarand tunneling toperations, .a..truck,..an tupwardlycextending pedestaksrn'onnted onzsaid truck, aucolumn ijournalledron saidilpedestalaor `rotation iabout. a f'verticalsaxis, :.drill supportsboomzmonnted .fons saidrcolumnnan taimpressure :chamber-the'fupper and dower-.twalls of Ywhichzar.efo1med, respe'ctivei.fbytsaid: columnaandgpedestalfmeansato `cleine a t relatively large air pressure reservoir xinteriorly .offsaid pedestal, saidreservoir ,communicating withfsaid air pressurechamber, andaneans. to .inject air .under,pressure .into saidY reservoir' .and a'ir chamber, .saidY irl in# ljection'bfeing under the control of an operator and .being intermittent during normalroperation .of'the .apparatus, wherby`the' air in said chamber serves to .maintain `said column "andboom *in*v an "elevated "position =for 'substanrtiailly"frictionlesseA pivoting aboutV said vertical axis, and the"'ai in saidereservoir maintains the fair' pressure inssaid chamber -'substantillyrconstant#during periods #-when; no :air-is :being injected. Y V9.fin;et:rockdrillingaapparatus, a'truck, Van upwardly 12 extendinghollcw. pedestal fnlountedon said truck.; ;a`;- 01' umn mounted .en said pedestal'ior .longitudinal movementrrelative "thereto` and for 4rotation ,abolita vltiqal axis, .a.;dr1l supporting iboom mountedzon said .colurnn for notation therewith, means to .denne .aniair chamber the upper .FM/.all .ofnwhichgeomprises a portion Aof said column and `the 'lowenwall `of` which comprises@ Portion 0f visaidgpedestal, ;a;p`iston mounted interiorly of said pedestal and :operablyconnectedxtoisaid column, thegworkingrsurfafce otisaid'ipiston having La larger iarea thansaid upper swall .fofsaid `airgshamber, and 1a single vsource fof airapressure :connected-gto saidyairgehamberand to Said pedestal above 'said .piston, ,said arrangement .operating to shift piston,columnzand boom zdownwardlyagainst the air-.pressurebias exerted againstsaidxportiongofesaid column.

10. Ina drilling. apparatus, Iannovable. support,azv.erti cally :disposed pedestal'lhavinga duid-tight hollow y'base anchoredon said-support, `a column. journalled .ou'isaid pedestal :for longitudinalshiftingf. relative Lthereto and -for rotationrahout a 'v eUtiCalaXiS, said columnfandigpedestal having relatively .smallrcooperating .shoulder portions forming,-:respective1y, :the .upper and lower wallsof an air chamber, said .colugnnqand pedestal valsoyhavingcooperating lock .'surfaceszadapted to comeinto lockingengagement `with .zeach tothenupon downward shifting fof said column, la drill-.supporting boom imounted. on said column,: a :relatively large tpiston monntedtin said hollow pedestal ibase `,-andeoperably associated :with y'said column .to fshiftrit:downwardlyinto flocking .engagement with'said ypedestal,conduit means: to admit .ain amder pressure into said 4.chamber tandtainto :said pedestal :base above fsaid piston, an'dfcheck valveirneans. to prevent the .escapelof air from-saidfchamber ronly,. whereby: said piston, column and Jboomnare: maintainediiin a ldepressed docking. :position during .application :of air .pressure-'tol said v1.conduitameans7 and are. shiftedeupwardly :l: y.-.the1residual-airl pressure fin said rchamberupon.' connection of saidconduitmeans fto avent. Y. f u

11. Ther invention `as zclaimed fin .claim i ll),V wherein the interior of saidipedestal abovesai'dghase is .sealediftoimm an air reservoir, and said reservoir is connectedxttorsaid .air 'chamber tot-.supply iairathereto.- after discontinuance 'of theair` pressure supply; through' said conduittmeans. .f .12. A rock drilling apparatus, comprising 1.a,truck,;.a vertically `disposed :tubularpedestal havingla holloxvebase fange .anchored :on-.said truck, ,said pedestal having 'n.- ternal wall Ymeansforrriinglapiston chamber. in saidxhase and an air reservoir-chamber above-:saidibase,` a tubular columnv journalled overl-said pedestallxandfhaving a'ffbase -i'lange shaped-to lock-withesaidbase.ilange ofsaidlpedf Iestal for prevention ofescolumn.\rotation,..1saidpedestal -and columnfbeingshaped .withcooperatingshoulders forming, fvrespectively,i .thetl'owec and vLupper .walls ,of ancair 'bearing chamber,V portv :means .to :connect saidrair bearing :and -airreservoir chambers,.:a:dri11 `supporting. boom, va horizontalfpivot :member-:seated on the. .upperend of .said .column.andrig-idlyconnectedv to Y said.` '.boom forl rotation fthereof `about :a :horizontal axis, Ea hinged cap .seated over saids-pivot-.memberfsa .piston zmounted intsaidtpiston `chamberfandfconnected ztosaid.l cap, said vpistonvbeingxof llarge area compared 5to the .upperfwall of said iairgbearing chamber, .-an'fair conduit connectedv Ato rsaid piston.' t'zham- Eber. abovesaidpiston.anditotsaid airbearing andi-reservoir -chambers,;andfcheck :valve-:meansvto preventfthegscape 0f a air from. said air reservoirfiand `airbearing;A chambers upon venting of the air in said piston chamber. 13. Ain -.a. drilling tapparatus,.-;a truck; a pedestalgan- @Choi-.ed aon said truck, n a; `column:` journalled'- .er1-.vy saidfpedzestal .for-'rotationtaboutgafvertical; axis, `a boom-mounted on said 'column land; mtaableg about aghorigontal tax-is, :means to; lock fsaidf boom against rotation, about said horizontalraxisf vdrill-, 1no,unted .at vtheQouter end .oft said lboom and-laterally.adjustableupon rotation ot saidboom and column about said Vertical axis, means to define a lock pressure chamber in said pedestal, liuid operated means associated with said lock pressure chamber to lock said column against rotation about said vertical axis upon admission of uid to said lock pressure chamber and to release said locking action upon venting of uid therefrom, a control valve mounted at said outer end of said boom, first conduit means in said boom to conduct .nid to said control valve, supply means to conduct uid to said rst conduit means, second conduit means to connect said control valve and said lock pressure chamber, and passage means in said control valve to alternately connect said first conduit means to said second conduit means, and said second conduit means to a vent.

14. In a rock drilling apparatus, a vehicle serving as a movable base member, a boom support member mounted on said base member, a boom assembly having one end portion mounted on said boom support member for upward and downward movement relative thereto and for rotation about a generally vertical axis, the other end portion of said boom assembly being adapted to support a rock drill, said boom support member including means cooperating therewith to define a fluid chamber an upper wall portion of which comprises a part of said one portion of said boom assembly, and means for supplying pressurized uid to said chamber and to maintain sucient pressure on said uid to support said boom assembly while permitting the boom assembly to rotate about said vertical axis with a minimum of friction.

15. The invention as claimed in claim 14, in which said iiuid is air, and a lower wall portion of said lluid chamber comprises a part of said boom support member.

16. The invention as claimed in claim l5, in which cooperating upper and lower lock surfaces are formed, respectively, on said one end portion of said boom assembly and on said boom support member, and in which iluid pressure means are provided to shift said one boom end portion downwardly until said lock surfaces are in locking engagement with each other, said last-named means being sutiiciently strong to overcome the supporting action of the uid in said uid chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,840,784 McMillan Jan. 12, 1932 1,842,026 Hulshizer Jan. 19, 1932 2,500,931 Curtis Mar. 2l, 1950 2,500,932 Curtis et al. Mar. 21, 1950 2,616,667 Dick Nov. 4, 1952 2,777,671 Fuehrer Jan. 15. 1957 

